Conventionally, there has been a DC-DC converter that compares a reference signal of a triangular wave with a feedback signal obtained by feeding back output voltage to determine duty, generates a PWM signal based on the determined duty, generates a drive signal by switching by a driver according to the PWM signal and outputs predetermined output voltage that is based on the drive signal.
In the DC-DC converter, noise is generated by switching by the driver, and the noise is propagated to other circuits via a transmission path such as power supply wiring. For example, the noise may be superimposed on the reference signal and the feedback signal. When mutually different noises are superimposed on the reference signal and the feedback signal, respectively, because of an impedance difference between transmission paths, jitter of a comparator signal increases, and operation of the DC-DC converter becomes unstable.